A method of producing a display panel such as a liquid crystal panel included in a display device as described below has been known. A pair of substrates one of which includes a thin film pattern of semiconductor elements such as thin film transistors (TFTs) are bonded to each other and a bonded substrate is formed. The bonded substrate is cut along an outline of the display panel and a display panel is produced.
A display panel produced with the above producing method generally has a front view of a square outline or a rectangular outline. Recently, according to variety of usage of the display panels, display panels having a non-rectangular outline such as an outline a part of which is curved have been produced. For example, Patent Document 1 discloses a method of producing a liquid crystal panel including a substantially ellipsoidal display area and, that is, a non-rectangular outline shape.